101–110 of 192 posts
Earlier quoted context omitted.
Erosion is not always wastage.
Could you expand? I'm interested in what you're getting at.
But we spend a lot of time and money managing erosion, and at the same time (often accidentally) create lots of erosion in other places. I doubt extracting tidal energy will have effects on a global scale, though it might cause some local changes
Interesting! Given the small amount of power relative to the total amount in the tides (I've seen an estimate of 3.7TW), this doesn't make a big difference to the Earth/Moon gravitational system, but I'm curious how this will affect the Moon's orbit (yes, I know it's millimeters or meters). For example, the Moon's orbit is increasing by stealing rotational energy from the Earth--i.e. Earth rotation slows down, Moon s…
Since the number 1.2MW didn't mean much to me, modern on-shore wind turbines seem to supply 3-4MW and offshore ones 8 - 12MW. But this seems a lot easier to transport and install compared to cranes and the nightmare of navigating turbine blades on trucks through places. And if these hold up to water and don't cause too many problems for wildlife, there would be a lot less discussions about these "messing up my skylin…
It is also a completely different scale. A 11M wind turbine has a 200m (!) rotor diameter. This thing is 12m.
More renewable is good.. but there is always one fear in my crazy mind about these: This isn't actually renewable but taking energy out of a huge reservoir (Same for solar if pea counting, but solar is really endless until the end of the solar system).. and if we'd scale it massively the result could be another catastrophe. (Same btw. with geothermal?). (Btw.. I maybe got tidal wrong, so if it is just taking energy f…
"Tidal Energy Is Not Renewable": https://cs.stanford.edu/people/zjl/pdf/tide.pdf Previous discussion on HN: https://news.ycombinator.com/item?id=37383283
TLDR, the 1000 year estimate is is derived from the geometric series proof(i needed a refresher). Wolfram explains it pretty well: https://mathworld.wolfram.com/GeometricSeries.html
...then i needed a refresher on exponents and logarithms: https://wou.edu/mathcenter/files/2015/09/Exponents-and-Logar...
It's good to do the math and think about the big picture sometimes. ;)
p.s. i tend to feel somewhat skeptical about a lot of renewable projects i read about in the news. And even if the math all works out and it really IS The Best Solution i cant help feeling we are ignoring the elephant in the room(population growth). Maybe human beings should start preparing themselves to live with less(and be happy with that).
Earlier quoted context omitted.
It's good that you are aware it's a crazy thought :) Nothing wrong with looking into it though. Wikipedia offers: > Movement of tides causes a loss of mechanical energy in the Earth-Moon system: this results from pumping of water through natural restrictions around coastlines and consequent viscous dissipation at the seabed and in turbulence. This loss of energy has caused the rotation of the Earth to slow in the 4.5…
> at this rate the Earth will stop rotating in 50 billion years, That's not what the link you posted says. It states that that's when the Earth-Moon system will be tidally locked, so that the Moon orbits the Earth at the same rate that the Earth rotates around its axis. Kind of if the earth slowed so that one "day" took the equivalent of 28 days now. The earth would be locked with one side always facing the moon, so…
Earlier quoted context omitted.
Alien archeologists from the future: "Earthlings caused a catastrophe by trying to suck every bit of tidal energy. Via tidal acceleration[^1], they made their natural satellite fall into their planet. The curious thing is that the kind of planetary technology level they deployed to extract energy from the tides was more than enough to build huge rotating habitats, which they even knew of and called O'Neill cylinders[…
Yeah I sometimes wonder about our use of energy. Like two whole percent goes to cracking puzzles, and if you prove you crack those puzzles we let you buy things. Those puzzles? Guessing hashes for Blockchain. Not cancer or science or engineering, just automated planet wide gambling. Then how much is used for ads? Like top to bottom, serving ads. Must be a ton. As a planetary anthropologist, seeing how much infra we b…
As for tiktok and silly dances, humans don't need only food and water to work reliably, they also need mental health. So leisure, amenities, relationships etc.(yeah tiktok included) are an addiction in the same sense food water and oxygen are an addiction, we just need them to work.(obviously while "addiction" to leisures is in general not a real problem, addiction to a specific thing in this list is, just like addiction to a specific food is a problem. I'm not saying tiktok addiction is a good thing)
If you think humanity's purpose is to develop their knowledge of the universe and techonological grasp, then i reassure you that(almost) everything we do on this spinning ball is a cog in the machine that ultimately sustains that development
Earlier quoted context omitted.
> at this rate the Earth will stop rotating in 50 billion years, That's not what the link you posted says. It states that that's when the Earth-Moon system will be tidally locked, so that the Moon orbits the Earth at the same rate that the Earth rotates around its axis. Kind of if the earth slowed so that one "day" took the equivalent of 28 days now. The earth would be locked with one side always facing the moon, so…
This is nice and all, but in 50 billion years, the moon's distance from the Earth will much greater which means it's gravitational effect on Earth will be much smaller.
If you've got what you think is a more accurate number, and can show your working, I'm sure the wikipedia editors would be willing to take a look at it.
Earlier quoted context omitted.
Yeah I sometimes wonder about our use of energy. Like two whole percent goes to cracking puzzles, and if you prove you crack those puzzles we let you buy things. Those puzzles? Guessing hashes for Blockchain. Not cancer or science or engineering, just automated planet wide gambling. Then how much is used for ads? Like top to bottom, serving ads. Must be a ton. As a planetary anthropologist, seeing how much infra we b…
I get your point with blockchain(altough i'd like a source for 2% of the entire human energy production going into it) but ads are useful actually, they make people know about what other people do which drives economy, and economy is basically a fancy word for the system that distributes each human's limited time into the various tasks society needs(which do include large scale planetary development but also for exam…
That's a bit too idealist a view for me. The economy isn't strictly or even mostly about fulfilling needs of society, but the aggregated demands of those with economic power, both wants and needs. A lot of what we spend effort on is not useful to society and a lot of needs go unmet. Certainly not every wasteful activity can be waved away as investing in our mental health. Some leisure is a net negative there, too. Some spending is destructive, with no upside. We humans are only somewhat-rational actors.